Interdependence of Electric Discharge and The Magnetorotational Instability in Protoplanetary Disks

Abstract

We study how the magnetorotational instability (MRI) in protoplanetary disks is affected by the electric discharge caused by the electric field in the resistive MHD. We have performed three-dimensional shearing box simulations with various values of plasma beta and electrical breakdown models. We find the self-sustainment of the MRI in spite of the high resistivity. The instability gives rise to the large electric field that causes the electrical breakdown, and the breakdown maintains the high ionization degree required for the instability. The condition for this self-sustained MRI is set by the balance between the energy supply from the shearing motion and the energy consumed by the Ohmic dissipation. We apply the condition to various disk models and study where the active, self-sustained, and dead zones of MRI are. In the fiducial minimum-mass solar nebula (MMSN) model, the newly-found sustained zone occupies only the limited volume of the disk. In the late-phase gas-depleted disk models, however, the sustained zone occupies larger volume of the disk.

23 pages, 9 figures,accepted to The Astrophysical Journal, Fix Figure 6

References in corpus (8)

• Photoevaporation of protoplanetary discs II: evolutionary models and observable properties
• Closed-form expressions for particle relative velocities induced by turbulence
• An Unsplit Godunov Method for Ideal MHD via Constrained Transport in Three Dimensions
• Photoevaporation of protoplanetary discs I: hydrodynamic models
• A Spitzer view of protoplanetary disks in the gamma Velorum cluster
• Magnetic fields in protoplanetary disks
• Planetesimal formation around the snow line in MRI-driven turbulent protoplanetary disks
• On the ionisation fraction in protoplanetary disks III. The effect of X-ray flares on gas-phase chemistry

Cited by in corpus (14)

• Magnetized Accretion and Dead Zones in Protostellar Disks
• Mineral Processing by Short Circuits in Protoplanetary Disks
• Short Circuits in Thermally Ionized Plasmas: A Mechanism for Intermittent Heating of Protoplanetary Disks
• Accretion in giant planet circumplanetary disks
• Temperature Fluctuations driven by Magnetorotational Instability in Protoplanetary Disks
• The Nonlinear Ohm's Law: Plasma Heating by Strong Electric Fields and its Effects on the Ionization Balance in Protoplanetary Disks
• Atmospheric electrification in dusty, reactive gases in the solar system and beyond
• Electron Heating in the Magnetorotational Instability: Implications for Turbulence Strength in Outer Regions of Protoplanetary Disks
• Electron Heating and Saturation of Self-regulating Magnetorotational Instability in Protoplanetary Disks
• Magnetic fields in gaps surrounding giant protoplanets
• The Generalized Nonlinear Ohm's Law: How a Strong Electric Field Influences Non-ideal MHD Effects in Dusty Protoplanetary Disks
• Flash ionisation signature in coherent cyclotron emission from Brown Dwarfs
• Development of a Method for the Observation of Lightning in Protoplanetary Disks Using Ion Lines
• The Dissolution of Planetesimals in Electrostatic Fields